2 Samuel 5:4

David was thirty years old when he began to reign; he reigned forty years.

1 Chronicles 26:31

Of the Hebronites was Jerijah the head; (as to the Hebronites, according to their families according to the fathers: in the fortieth year of the reign of David they were sought for, and there were found among them mighty men of valour at Jaazer in Gilead;)

1 Chronicles 29:27

And the time that he reigned over Israel was forty years: he reigned seven years in Hebron, and he reigned thirty-three years in Jerusalem.

Luke 3:23

And Jesus himself was beginning to be about thirty years old; being as was supposed son of Joseph; of Eli,

1 Kings 2:11

And the days that David reigned over Israel were forty years: he reigned seven years in Hebron, and he reigned thirty-three years in Jerusalem.

1 Chronicles 3:4

six were born to him in Hebron. And there he reigned seven years and six months. And in Jerusalem he reigned thirty-three years.

Treasury of Scripture Knowledge

Summary

David was thirty years old when he began to reign, and he reigned forty years.

Thirty

Bible References

Thirty

Luke 3:23
And Jesus himself was beginning to be about thirty years old; being as was supposed son of Joseph; of Eli,

Forty

1 Chronicles 26:31
Of the Hebronites was Jerijah the head; (as to the Hebronites, according to their families according to the fathers: in the fortieth year of the reign of David they were sought for, and there were found among them mighty men of valour at Jaazer in Gilead;)
1 Chronicles 29:27
And the time that he reigned over Israel was forty years: he reigned seven years in Hebron, and he reigned thirty-three years in Jerusalem.